TABLE 1. Characteristics associated with incidence of symptomatic human metapneumovirus infection — CASCADIA community cohort (N = 3,549), Oregon and Washington, June 2022–March 2024.
| Characteristic | Total cases/Total person-years | Incidence* (95% CI) | Hazard ratio (95% CI) |
|
|---|---|---|---|---|
| Unadjusted | Adjusted† | |||
|
Overall
|
306/4,072
|
7.5 (6.7–8.4)
|
—
|
—
|
|
Age group during follow-up
| ||||
| 6–23 mos |
10/74
|
13.5 (7.3–25.1) |
3.6 (1.8–7.1) |
3.7 (1.8–7.6) |
| 2–4 yrs |
51/261
|
19.5 (14.9–25.7) |
5.3 (3.6–7.9) |
5.8 (3.8–9.0) |
| 5–11 yrs |
114/999
|
11.4 (9.5–13.7) |
3.0 (2.2–4.1) |
3.1 (2.2–4.5) |
| 12–17 yrs |
46/6,517
|
7.1 (5.3–9.4) |
1.9 (1.3–2.8) |
2.0 (1.4–3.1) |
| 18–39 yrs |
29/6,234
|
4.7 (3.2–6.7) |
1.2 (0.8–2.0) |
1.2 (0.8–1.9) |
| ≥40 yrs |
56/1,462
|
3.8 (2.9–5.0) |
Ref |
Ref |
|
Sex
| ||||
| Female |
183/2,369
|
7.7 (6.7–8.9) |
Ref |
Ref |
| Male |
123/1,703
|
7.2 (6.1–8.6) |
0.9 (0.7–1.2) |
0.8 (0.6–1.0) |
|
Race and ethnicity
| ||||
| White, NH |
206/2,916
|
7.1 (6.2–8.1) |
Ref |
Ref |
| Other§ |
100/1,156
|
8.7 (7.1–10.5) |
1.2 (1.0–1.6) |
1.1 (0.8–1.4) |
|
No. of persons reported in household¶
| ||||
| 1–2 |
18/271
|
6.6 (4.2–10.5) |
Ref |
Ref |
| 3 |
61/920
|
6.6 (5.2–8.5) |
1.0 (0.6–1.7) |
0.8 (0.5–1.4) |
| 4 |
154/1,995
|
7.7 (6.6–9.0) |
1.2 (0.7–2.0) |
0.9 (0.5–1.5) |
| ≥5 |
73/886
|
8.2 (6.5–10.4) |
1.2 (0.7–2.1) |
0.9 (0.5–1.5) |
|
No. of children reported in household**
| ||||
| 0 |
5/117
|
4.3 (1.8–10.3) |
Ref |
Ref |
| 1 |
76/1,040
|
7.3 (5.8–9.1) |
1.7 (0.7–4.4) |
1.1 (0.4–2.9) |
| 2 |
161/2,138
|
7.5 (6.5–8.8) |
1.8 (0.7–4.4) |
1.0 (0.4–2.6) |
| ≥3 |
64/776
|
8.2 (6.5–10.5) |
1.9 (0.8–5.0) |
1.1 (0.4–2.8) |
|
Household income (USD)
| ||||
| <100,000 |
63/905
|
7.0 (5.4–8.9) |
Ref |
Ref |
| 100,000–199,000 |
105/1,518
|
6.9 (5.7–8.4) |
1.0 (0.7–1.4) |
1.0 (0.7–1.5) |
| ≥200,000 |
120/1,381
|
8.7 (7.3–10.4) |
1.3 (0.9–1.8) |
1.2 (0.8–1.7) |
| Prefer not to answer |
18/268
|
6.7 (4.2–10.7) |
0.9 (0.5–1.7) |
0.9 (0.5–1.6) |
|
Health insurance status
| ||||
| Employer or individual |
281/3,576
|
7.9 (7.0–8.8) |
Ref |
Ref |
| Medicaid, Medicare, or other government insurance |
17/296
|
5.7 (3.6–9.2) |
0.7 (0.4–1.3) |
0.6 (0.4–1.2) |
| Other†† |
8/167
|
4.8 (2.4–9.6) |
0.6 (0.3–1.2) |
0.5 (0.2–1.1) |
|
Underlying health condition
| ||||
| No |
217/2,453
|
8.8 (7.7–10.1) |
Ref |
Ref |
| Yes |
89/1,619
|
5.5 (4.5–6.8) |
0.6 (0.5–0.8) |
1.1 (0.8–1.5) |
|
Year
| ||||
| Year 1 (Jun 19, 2022–Jun 18, 2023) |
235/1,757
|
13.4 (11.8–15.2) |
4.4 (3.4–5.8) |
3.5 (2.6–4.6) |
| Year 2 (Jun 19, 2023–Mar 30, 2024) |
71/2,315
|
3.1 (2.4–3.9) |
Ref |
Ref |
|
Q
| ||||
| Q1 (Jan–Mar) |
208/1,273
|
16.3 (14.3–18.7) |
5.0 (3.6–7.0) |
4.3 (3.0–6.0) |
| Q2 (Apr–Jun) |
51/742
|
6.9 (5.2–9.0) |
2.1 (1.4–3.2) |
1.2 (0.8–1.9) |
| Q3 (Jul–Sep) |
8/860
|
0.9 (0.5–1.9) |
0.3 (0.1–0.6) |
0.4 (0.2–0.9) |
| Q4 (Oct–Dec) |
39/1,197
|
3.3 (2.4–4.5) |
Ref |
Ref |
|
Study site
| ||||
| Kaiser Permanente Northwest |
129/1,960
|
6.6 (5.5–7.8) |
Ref |
Ref |
| University of Washington | 177/2,112 | 8.4 (7.2–9.7) | 1.3 (1.0–1.6) | 1.2 (0.9–1.6) |
Abbreviations: NH = non-Hispanic; Q = quarter; Ref = referent group; USD = U.S. dollars.
* Cases per 100 persons per year.
† Models were adjusted for age group, sex, race and ethnicity, year, Q of the year, household size, household income, and presence of underlying health conditions. Household size was omitted from the model of the number of children in the household because of collinearity.
§ Includes NH American Indian or Alaska Native, NH Asian, NH Black or African American, NH Native Hawaiian or Pacific Islander, Hispanic or Latino (Hispanic), NH multiple races, and preferred not to say.
¶ Median of three members enrolled per household (range = one to eight), with a median of two members aged ≥18 years enrolled per household (range = one to four).
** Median of two children aged <18 years (range = one to six) enrolled per household.
†† Includes no insurance, other insurance, don’t know, and preferred not to say.